The present invention relates to a steel which exhibits excellent abrasion-resistance and corrosion resistance in a state exposed to abrasive abrasion and a weaving machine member, e.g. a flat steel heald, a dropper, a reed dent or a tunnel reed, which is likely abraded in contact with fibers.
High-strength steels such as cutlery steel or tool steel have been used so far for such uses necessary of abrasion-resistance, e.g. a weaving machine member subjected to abrasion in contact with threads, and an electric or electronic member subjected to abrasion in contact with other members. Corrosion-resistance is also one of requisitions for such steels, accounting use environments.
Although cutters, tools, weaving machine members, electric members or electronic members largely changes their durability in response to use environment, abrasion resistant of steel material puts biggest influence on the durability. In this regard, a carbon steel having a metallurgical structure hardened by quenching or cold-working has been used as a member necessary of abrasion-resistance.
For instance, a structure-hardened steel prepared by quenching a stainless steel SUS420J2 has been used so far as weaving machine members such as a flat steel heald, a dropper, a reed dent and a tunnel reed. Such the weaving machine members are subjected to a severer and severer abrading environment in response to material improvement of fibers used for fabrics and high-speed processing for enhance of productivity. As a result, a lifetime of the members becomes shorter and shorter, and the members are necessarily exchanged for new members with a high frequency.
Since abrasion is the phenomenon which occurs under very complicated mechanisms, causes of abrasion at abraded parts have not been clarified yet, but high-strength steels have been used with estimation of necessary abrasion-resistance. In short, durability of a steel member has been evaluated in the state that the steel member is actually incorporated in an existing machine. As a result, it needs a fairly long time to choose a proper steel kind, and proper selection of the steel kind is also difficult.
Abrasion-resistance of a steel can be improved by structure-hardening or work-hardening. However, abrasive environments is getting more severe in response to enhancement of productivity which needs high-speed processing or use of tough materials to be processed. Such severely abrading environments decrease durability of steel members, resulting in frequent exchange of steel members and occurrence of damages derived from abrasion. The damages derived from abrasion are varied in response to abrading conditions, and hardness is not always proportional to durability of steel members. In this sense, it is important to sufficiently recognize abrading mechanisms in use environments for developments of steel kinds suitable for such environments.
The present invention is accomplished for fulfillment of such requisitions, aiming at provision of a new steel which sufficiently endures excessive abrasion by dispersion of hard carbide precipitates in a steel matrix and especially at provision of a weaving machine member, which can be used for a long time, made of a steel excellent in abrasion-resistance even under severe abrading conditions.
The newly proposed steel consists essentially of 8.0-35.0 wt. % Cr, 0.05-1.20 wt. % C, 0.05-3.0 wt. % at least one of Ti, Nb, Zr, V and W, and has the structure that an amount of Ti, Nb, Zr, V and/or W carbides precipitates distributed in a steel matrix is adjusted to 0.1 wt. % or more in total.
The weaving machine member according to the present invention is made of a steel essentially consisting of 8.0-35.0 wt. % Cr, 0.05-1.0 wt. % C, up to 1.0 wt. % Si, up to 1.0 wt. % Mn, one or two of 0.05-1.0 wt. % Ti and 0.05-1.50 wt. % Nb with the proviso of 0.05-2.0 wt. % in total and the balance being Fe except inevitable impurities, and having the structure that a total amount of Ti and/or Nb carbide precipitates distributed in a steel matrix is adjusted to 0.1 wt. % or more.